New retainer material for high speed and high temperature cylindrical roller bearing

Cylindrical roller bearings are being developed which can operate over 300 degrees C and greater than three million DN for innovative gas-generators. Under such severe conditions, it is necessary for retainers to be frictionl ess, lightweight and strong. After preliminary resting, SiC particle reinfo rced aluminum alloy composite appeared to have good friction and wear prope rties. It's specific gravity is about one-third of the present material in use. silver-coated SAE4340. in the course of the study, two different frict ion and wear tests were conducted to investigate the optimum volume fractio n of SiC. The results indicated that the most efficient volume fraction was 20vol%. The tensile strength of Al20vol%SiC was about 140MPa at 300 degree s C. Based on the results of FEM analysis, 140MPa is considered sufficient to endure any stress concentration caused by tensile hoop stresses up to fo ur million DN.